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FieldCalculate Feature Class Attribute values by matching existing field values to dictionary

WilliamKalande

</CODE></PRE></BLOCKQUOTE><P>I have a dictionary whose keys also appear are attribute values in a fc_1.</P><P>In the code below, I use the dictionary&nbsp;values to select by attribute rows (gid) in fc_1 with intention of writing the dictionary keys into another field in&nbsp;<SPAN>fc_1</SPAN> using&nbsp;arcpy.SelectLayerByAttribute_management.</P><P></P><P>This only writes the last key in the dictionary against all the selected values.</P><P></P><BLOCKQUOTE class="jive_macro_quote jive-quote jive_text_macro"><BLOCKQUOTE class="jive_macro_quote jive-quote jive_text_macro"><PRE class="lia-code-sample line-numbers language-none"><CODE>import arcpy

arcpy.env.workspace = r'home\delete\cccgdb.gdb'
gc = 'fc_1'
field ='FIDF'
dictio={"a": "AAA", "b": "BBB", "c": "CCC", "d": "DDD"}
fc_1_lyr = arcpy.MakeFeatureLayer_management(gc, "fc_1_lyr")
for i in dictio.keys():
&nbsp; &nbsp; &nbsp;for j in dictio.values():
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;#print (j)
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;whereClause = "gid = '%s'"%j
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;print (whereClause)
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;act = arcpy.SelectLayerByAttribute_management(fc_1_lyr, 'NEW_SELECTION', whereClause)
&nbsp; &nbsp; &nbsp; &nbsp;  expression ='%s'%i
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;print(expression)
&nbsp; &nbsp; &nbsp; &nbsp; &nbsp;arcpy.CalculateField_management(act, field, expression)
&nbsp; &nbsp; &nbsp; &nbsp;  arcpy.SelectLayerByAttribute_management(fc_1_lyr, "CLEAR_SELECTION")


print ('memaliza')‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

What am I doing wrong?

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Accepted answers

JoshuaBixby

Try the following structure:

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> dictio<SPAN class="operator token">=</SPAN><SPAN class="punctuation token">{</SPAN><SPAN class="string token">"a"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"AAA"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"b"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"BBB"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"c"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"CCC"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"d"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"DDD"</SPAN><SPAN class="punctuation token">}</SPAN>
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> <SPAN class="keyword token">for</SPAN> k<SPAN class="punctuation token">,</SPAN> v <SPAN class="keyword token">in</SPAN> dictio<SPAN class="punctuation token">.</SPAN>items<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     whereClause <SPAN class="operator token">=</SPAN> <SPAN class="string token">"gid = '%s'"</SPAN><SPAN class="operator token">%</SPAN>v
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     <SPAN class="keyword token">print</SPAN> <SPAN class="punctuation token">(</SPAN>whereClause<SPAN class="punctuation token">)</SPAN>
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     expression <SPAN class="operator token">=</SPAN><SPAN class="string token">'%s'</SPAN><SPAN class="operator token">%</SPAN>k
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>expression<SPAN class="punctuation token">)</SPAN>
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'AAA'</SPAN>
a
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'BBB'</SPAN>
b
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'CCC'</SPAN>
c
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'DDD'</SPAN>
d
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

All comments

wwnde

Thanks. Edited as below. Working well.

import arcpy
arcpy.env.workspace = r'home\Desktop\delete\cccgdb.gdb'
gc = 'fc_1'
field =['FIDF', 'gid']
dictio={"a": "AAA", "b": "BBB", "c": "CCC", "d": "DDD"}
fc_1_lyr = arcpy.MakeFeatureLayer_management(gc, "fc_1_lyr")
for k, v in dictio.items():
        whereClause = '%s'%v
        expression ='%s'%k
        with arcpy.da.UpdateCursor(gc, field) as cursor: 
            for row in cursor: 
                if row[1] == whereClause:
                   row[0] = expression
                   cursor.updateRow(row) 
 
print ('memaliza')‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍<SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Cheers

JoshuaBixby

Try the following structure:

<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> dictio<SPAN class="operator token">=</SPAN><SPAN class="punctuation token">{</SPAN><SPAN class="string token">"a"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"AAA"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"b"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"BBB"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"c"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"CCC"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"d"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"DDD"</SPAN><SPAN class="punctuation token">}</SPAN>
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN> <SPAN class="keyword token">for</SPAN> k<SPAN class="punctuation token">,</SPAN> v <SPAN class="keyword token">in</SPAN> dictio<SPAN class="punctuation token">.</SPAN>items<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     whereClause <SPAN class="operator token">=</SPAN> <SPAN class="string token">"gid = '%s'"</SPAN><SPAN class="operator token">%</SPAN>v
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     <SPAN class="keyword token">print</SPAN> <SPAN class="punctuation token">(</SPAN>whereClause<SPAN class="punctuation token">)</SPAN>
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     expression <SPAN class="operator token">=</SPAN><SPAN class="string token">'%s'</SPAN><SPAN class="operator token">%</SPAN>k
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>     <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>expression<SPAN class="punctuation token">)</SPAN>
<SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN><SPAN class="punctuation token">.</SPAN>
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'AAA'</SPAN>
a
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'BBB'</SPAN>
b
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'CCC'</SPAN>
c
gid <SPAN class="operator token">=</SPAN> <SPAN class="string token">'DDD'</SPAN>
d
<SPAN class="operator token">>></SPAN><SPAN class="operator token">></SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

WilliamKalande

Edited code. I have dropped the legacy cursor and picked ArcPy cursors later in the code. Thanks

I use gc in a later section of the code which is running well. Have however edited to put it to immediate use in this section.

Why I used dictio is because it didnt matter whether I picked A OR AAA. I however have modified to ensure it picks the entire dictionary value say AAA OR DDD. Still not successful. My output

gid = 'AAA'
a
gid = 'CCC'
a
gid = 'BBB'
a
gid = 'DDD'
a
gid = 'AAA'
c

whereeas my desired result is

gid = 'AAA'
a
gid = 'CCC'
c
gid = 'BBB'
b
gid = 'DDD'
d

and these values should be written in the attribute table. At the moment, its writing d in all the rows.

JoshuaBixby

Please read /blogs/dan_patterson/2016/08/14/script-formatting?sr=search&searchId=d5742ea6-9b0b-40f2-a083-9fbbc0d31348&searchIndex=3‌, or watch the video /blogs/sergent/2015/02/18/formatting-your-code-in-geonet-for-the-visual-learner?sr=search&searchId=d5742ea6-9b0b-40f2-a083-9fbbc0d31348&searchIndex=2‌.

Formatting your original code snippet:

<SPAN class="keyword token">import</SPAN> arcpy
<SPAN class="keyword token">from</SPAN> arcpy <SPAN class="keyword token">import</SPAN> SearchCursor
arcpy<SPAN class="punctuation token">.</SPAN>env<SPAN class="punctuation token">.</SPAN>workspace <SPAN class="operator token">=</SPAN> r<SPAN class="string token">'home\delete\cccgdb.gdb'</SPAN>
gc <SPAN class="operator token">=</SPAN> <SPAN class="string token">'fc_1'</SPAN>
field <SPAN class="operator token">=</SPAN><SPAN class="string token">'FIDF'</SPAN>
dictio<SPAN class="operator token">=</SPAN><SPAN class="punctuation token">{</SPAN><SPAN class="string token">"a"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"AAA"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"b"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"BBB"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"c"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"CCC"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"d"</SPAN><SPAN class="punctuation token">:</SPAN> <SPAN class="string token">"DDD"</SPAN><SPAN class="punctuation token">}</SPAN>
fc_1_lyr <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>MakeFeatureLayer_management<SPAN class="punctuation token">(</SPAN><SPAN class="string token">"fc_1"</SPAN><SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"fc_1_lyr"</SPAN><SPAN class="punctuation token">)</SPAN>
<SPAN class="keyword token">for</SPAN> i <SPAN class="keyword token">in</SPAN> dictio<SPAN class="punctuation token">.</SPAN>keys<SPAN class="punctuation token">(</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="punctuation token">:</SPAN>
     <SPAN class="keyword token">for</SPAN> j <SPAN class="keyword token">in</SPAN> dictio<SPAN class="punctuation token">[</SPAN>i<SPAN class="punctuation token">]</SPAN><SPAN class="punctuation token">:</SPAN>
         <SPAN class="comment token">#print (j)</SPAN>
         whereClause <SPAN class="operator token">=</SPAN> <SPAN class="string token">"gid = '%s'"</SPAN><SPAN class="operator token">%</SPAN>j
         <SPAN class="keyword token">print</SPAN> <SPAN class="punctuation token">(</SPAN>whereClause<SPAN class="punctuation token">)</SPAN>
         act <SPAN class="operator token">=</SPAN> arcpy<SPAN class="punctuation token">.</SPAN>SelectLayerByAttribute_management<SPAN class="punctuation token">(</SPAN>fc_1_lyr<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">'NEW_SELECTION'</SPAN><SPAN class="punctuation token">,</SPAN> whereClause<SPAN class="punctuation token">)</SPAN>
         expression <SPAN class="operator token">=</SPAN><SPAN class="string token">'%s'</SPAN><SPAN class="operator token">%</SPAN>i
         <SPAN class="keyword token">print</SPAN><SPAN class="punctuation token">(</SPAN>expression<SPAN class="punctuation token">)</SPAN>
         arcpy<SPAN class="punctuation token">.</SPAN>CalculateField_management<SPAN class="punctuation token">(</SPAN>act<SPAN class="punctuation token">,</SPAN> field<SPAN class="punctuation token">,</SPAN> expression<SPAN class="punctuation token">)</SPAN>
         arcpy<SPAN class="punctuation token">.</SPAN>SelectLayerByAttribute_management<SPAN class="punctuation token">(</SPAN>fc_1_lyr<SPAN class="punctuation token">,</SPAN> <SPAN class="string token">"CLEAR_SELECTION"</SPAN><SPAN class="punctuation token">)</SPAN>


<SPAN class="keyword token">print</SPAN> <SPAN class="punctuation token">(</SPAN><SPAN class="string token">'memaliza'</SPAN><SPAN class="punctuation token">)</SPAN><SPAN class="line-numbers-rows"><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN><SPAN>‍</SPAN></SPAN>

Some questions/comments:

You are importing SearchCursor but are not using it. If you are using ArcPy cursors somewhere later in the code, I suggest using SearchCursor—Data Access module | ArcGIS Desktop instead of the legacy cursor.
You define a gc variable but never use it.
I am not sure if Line #9 is doing what you think, or maybe I don't understand what you are trying to do. Since your dictionary is storing strings, dictio will return a string and for j will loop over each letter in the string. Do you really want to create 3 identical WHERE clauses, e.g., gid = 'A', gid = 'A', gid = 'A' ?

WilliamKalande

Edited. Well indented in code. Didnt paste well in here

JoeBorgione

For starters, format your text so it can be read: the lines in your nested for loop don't appear to be indented correctly (or are they?).

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